The present invention relates to an automatic car following control system wherein a throttle valve is automatically controlled, and more particularly to the system for controlling the throttle valve in accordance with a desired magnitude of acceleration in a longitudinal direction of a vehicle.
In an example of the automatic following control system, a plurality of cameras are mounted on the vehicle to monitor forward conditions such as a behaviour of a front-running vehicle (a vehicle which is riding in front of a present vehicle equipped with the automatic following control system). A control unit processes image data picked up by the camera to determine acceleration and deceleration of the front-running vehicle, and drives a motor to operate the throttle valve of the present vehicle dependent on the acceleration and deceleration of the front-running vehicle. More particularly, the control unit determines a desired throttle opening degree in accordance with the detected distance between the front-running vehicle and the present vehicle, and the vehicle speed of the present vehicle. Thus, the engine power and the behaviour of the vehicle is controlled in dependency on the determined desired throttle opening degree.
Japanese Patent Application Laid-Open 2-149738 discloses a system for controlling the opening degree of the throttle valve wherein a desired throttle opening degree is calculated in accordance with a desired boost value. Namely, the throttle valve is controlled in dependency mainly on the engine power. Consequently, the vehicle is rapidly accelerated or decelerated to comply with the desired increase or decrease of the engine power. Hence, the vehicle speed abruptly changes so that the vehicle does not ride smoothly.